In the oil and gas industries, coiled tubing refers to a very long metal pipe supplied spooled on a large reel. It is used for interventions in oil and gas wells and sometimes as production tubing in depleted gas wells. A relatively modern drilling technique involves using coiled tubing instead of conventional drill pipe.
FIG. 1 illustrates generally a coiled tubing setup. The coiled tubing is fed from a reel into the injector which effectively powers the tubing into the wellhead. The end of the coiled tubing string can be outfitted with numerous downhole tools including drill bits and other related drilling equipment. The “gooseneck” is the angled piece on the injector which guides the tubing and allows a bending of the coil string to allow it to go through the injector. It is what guides the tubing from the reel and directs the tubing from an upwards angle and turns it into a vertically downward extending direction into the injector and a device called a “stripper”, which contains pack off elements and hydraulically seals the tubing before entering the wellhead. The stripper acts as packing device that allows the tubing to be sealed around the wellhead and blowout preventer (BOP) to prevent backflow of fluids from the well. The injector and gooseneck are connected together and are suspended by a crane or similar lifted methods for operations.
The typical stripper adapter plate that is on a coiled tubing injector is outfitted for one particular tubing size, and is not adjustable to fit numerous tubing sizes. Instead, the stripper adapter plate must be changed out to adjust to different tubing sizes. Different stripper adapter plate manufacturers may have different mounting or hole patterns that do not always correspond with equipment or components not their own. Thus, having a universal plate or a plate that can be changed out to meet any size or brand stripper would be very beneficial in reducing onsite well time, thus improving safety and reducing costs. Similarly, proper alignment of all equipment is important as misalignment case affect the operational efficiency of the coiled tubing unit.
FIG. 2 illustrates a prior stripper mount 100. Most stripper mounts are attached to the bottom of the injector with rails, large pins 101, or other devices that need to be removed that will allow the removal of the stripper adapter. Typical designs have two large devices that are locked into place on either side of the plate, which allow stability. Most stripper mounts need to be changed when the unit is still on the trailer, or a more risky method of approaching the unit from underneath while suspended by a crane or lifting device. The entire adapter must be removed in order to change the size of the tubing, which results in crews having to keep several size adapters in stock, or as back-ups for a failing unit or a defective unit. The units packing does fail, and can be significantly detrimental to operations to have one fail during operation.
Further disadvantages are that the bolt pattern 103 does not rotate freely, and the stripper adapter 104 stays stationary relative to the base 102, so if the wellhead bolt holes are not aligned the operator must pivot the injector, and force the injector into an unnatural non-linear state, which can be detrimental to operational efficiency and cause equipment degradation. Further disadvantages include wasted time on jobsites attempting to pivot the injector head to mate up properly, some crews might even have to completely rigdown equipment and reposition on wells in order for the stripper plate to align with the wellhead.